The Main Difference between Linear and Nonlinear Circuit

Linear Circuit

In simple words, a linear circuit is an electric circuit in which circuit parameters (Resistance, inductance, capacitance, waveform, frequency etc) are constant. In other words, a circuit whose parameters are not changed with respect to Current and Voltage is called Linear Circuit.

Fundamentally, the word “linear” literally means “along with a straight line”. As the name tells everything, a linear circuit means linear characteristics in between Current and Voltage, which means, current flowing through a circuit is directly proportional to the applied Voltage.

If we increase the applied voltage, then the current flowing through the circuit will also increase, and vice versa. If we draw the circuit output characteristic curve in between Current and Voltage, it will look like a straight line (Diagonal) as shown in fig (1).

In a linear circuit, the output response of the circuit is directly proportional to the input. Simple Explanation of the above statement is,

in an electric circuit, in which the applied sinusoidal voltage having frequency “f”, the output (Current through a component or Voltage between two points) of that circuit is also sinusoidal having frequency “f”.

Click image to enlarge

Linear Circuit and its characteristic curve is shown in below fig (1).

Examples of Liner Circuits and Linear Elements

Resistance and Resistive Circuit

Inductor and Inductive Circuits

Capacitor and Capacitive Circuits

Non Linear Circuit

A nonlinear circuit is an electric circuit whose parameters are varied with respect to Current and Voltage. In other words, an electric circuit in which circuit parameters (Resistance, inductance, capacitance, waveform, frequency etc) is not constant, is called Non Linear Circuit.

If we draw the circuit output characteristic curve in between Current and Voltage, it will look like a curved or bending line as shown in fig (2).

Click image to enlarge

Non Linear Circuit and its characteristic curve are shown in below fig (2).

Examples of Non-Liner Circuits and Non Linear Elements

Diode

Transistor

Transformer

Iron Core

inductor (when the core is saturated)

and any circuit composed exclusively of ideal Diode,

Transistor

Transformer

and Iron Core inductor is called Non linear circuit.

Solving Linear and Nonlinear Circuits

Solving of a nonlinear circuit is a little bit complex then linear circuits. Linear circuit can be solved with simple techniques and scientific calculator. While solving Non linear circuits, a lot of data and information is required.

But nowadays, due to aggressive technological changes and Modernization, we can simulate and analyze, with output curves both linear and non linear circuits very easily with the help of circuit simulation tools like PSpice , MATLAB, Multisim etc.

I was thinking the same thing like that contradicts to what the title above says. Luckily I went to another site to verify what that paragraph says and found some useful info on diodes and exponential growth so if anything whoever wrote the article thanks for screwing that part up.